Rekey vs. Replace Locks: Which Do You Need?

When you want to control who can open your door, you have two options: rekey the existing locks or replace them entirely. They achieve different things at very different price points, and knowing which you actually need can save you a lot of money.

What "rekeying" actually means

Rekeying keeps your existing lock hardware but changes the small pins inside the cylinder so that a new key works and every old key stops working. The lock on your door looks and functions exactly the same — it just answers to a different key now. A locksmith can rekey a typical lock in a few minutes, and can set several locks to open with one key at the same time.

What "replacing" means

Replacing removes the entire lock and installs a brand-new one. You get new hardware, a new finish, and any new features the new lock offers. It costs more because you are paying for the hardware plus installation, but sometimes it is the only option that makes sense.

When to rekey

• You just moved in. You have no idea how many copies of the old keys exist — previous owners, tradespeople, neighbours, realtors. Rekeying instantly makes them all useless.
• You lost your keys. If keys are missing or stolen, rekeying is the fast, affordable way to make sure they no longer open your door.
• You want one key for everything. A locksmith can rekey multiple locks to match a single key, so you carry less.
• A roommate or tenant moved out. Rekeying resets access without buying new hardware.

When to replace

• The lock is worn or damaged. If it sticks, is loose, or has failed, a rekey will not fix the underlying hardware.
• You want an upgrade. Moving to a high-security lock, a proper deadbolt, or a smart or keypad lock requires new hardware.
• The look no longer fits. Dated or mismatched hardware is a replace-only fix.
• The locks are very old. Some older or worn cylinders are not worth rekeying and are better replaced.

The cost difference

Rekeying is dramatically cheaper — typically a small per-cylinder charge plus a service call, versus paying for new hardware on every door when you replace. For most people moving into a new home, rekeying every exterior lock to a single new key is the smart, budget-friendly choice. Replacement is worth it when you are also upgrading security or the hardware is past its life.

Not sure which applies to your doors? A locksmith can assess each lock and tell you honestly whether a quick rekey will do or whether replacement is the better value.